The White House announced Saturday that President Barack Obama would be unable to attend the state funeral for Poland’s late president because of the volcanic ash that has stopped air travel all over northern Europe.

“I spoke with acting President [Bronislaw] Komorowski and told him that I regret that I will not be able to make it to Poland due to the volcanic ash that is disrupting air travel over Europe,” Obama said in a statement issued by the White House. “Michelle and I continue to have the Polish people in our thoughts and prayers, and will support them in any way I can as they recover from this terrible tragedy. President [Lech] Kaczynski was a patriot and close friend and ally of the United States, as were those who died alongside him, and the American people will never forget the lives they led.”